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• Stack Structure
The stack structure of PC at a subroutine branch and that of PC and CCR at an exception
handling branch are shown in figure 2.5. The PC contents are saved or restored in 24-bit units.
SP
Notes: 1.
Figure 2.5 Stack Structure in Middle and Advanced Modes
2.2.4
Maximum Mode
The program area in maximum mode is extended to 4 Gbytes as compared with that in advanced
mode.
• Address Space
A maximum address space of 4 Gbytes can be linearly accessed.
• Extended Registers (En)
The extended registers (E0 to E7) can be used as 16-bit registers or as the upper 16-bit
segments of 32-bit registers or address registers.
• Instruction Set
All instructions and addressing modes can be used.
• Exception Handling Vector Table and Memory Indirect Branch Addresses
In maximum mode, the top area starting at H'00000000 is allocated to the exception handling
vector table in 32-bit units. One branch address is stored in 32 bits. The structure of the
exception handling vector table is shown in figure 2.6.
Reserved
PC
(24 bits)
(a) Subroutine Branch
When EXR is not used it is not stored on the stack.
2.
SP when EXR is not used.
3.
Ignored on return.
SP
EXR*
Reserved*
2
*
(SP
)
CCR
PC
(24 bits)
(b) Exception Handling
Rev.2.00 Jun. 28, 2007 Page 21 of 666
Section 2 CPU
1
1
3
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REJ09B0311-0200
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